The field of the disclosure is systems and methods for magnetic resonance imaging (“MRI”). More particularly, the disclosure relates to systems and methods for multi-echo background-suppressed magnetic resonance angiography (MRA).
Peripheral vascular disease (PVD) has an age-adjusted prevalence of 12% in the United States, causes significant morbidity, and is often associated with excess cardiovascular mortality. Contrast-enhanced (CE) magnetic resonance angiography (MRA) often substitutes for the more invasive “gold standard” procedure of digital subtraction angiography. Given the frequency of renal functional impairment in patients with PVD and concerns about nephrogenic systemic fibrosis, there is growing interest in non-contrast-enhanced MRA.
Quiescent-interval slice-selective (QISS) MRA has is an efficient and accurate non-contrast technique for the evaluation of peripheral arterial disease. In QISS MRA, the MRI system acquires data using a modified single shot two-dimensional balanced steady-state free precession (bSSFP) pulse sequence. Unlike subtractive non-contrast-enhanced three-dimensional MRA methods, the imaging parameters for QISS MRA require minimal if any tailoring for individual patients. However, compared with CE-MRA, the bSSFP readout used for QISS is more sensitive to susceptibility effects.
For example, in certain circumstances such as imaging near a metallic hip prosthesis or at 3 Tesla near an air-containing bowel loop, the image quality may be degraded by susceptibility artifacts due to the use of a bSSFP readout. A high bandwidth and short TE may reduce artifacts at the expense of worsening small vessel conspicuity on projection images.
It would therefore be desirable to provide MRI systems and methods with enhanced background suppression to overcome the above limitations.